Index mechanism



Dec. 19, 1939. C, GR 2,183,864

INDEX MECHANISM Fild March 29, 1959 CLHHENEE J.GREEN Patented Dec. 19,1939 INDEX MECHANISM Clarence J. Green, Worcester, Mass.,-assignor toNorton Company, Worcester, Mass., a corporation of MassachusettsApplication March 29, 1939, Serial No. 264,795

, 4 Claims.

The invention relates to indexing mechanism, particularly for automaticcamshaft grinding machines such as disclosed in patent to Belden andSilven No. 2,022,178.

One object of the invention is to permit an automatic camshaft grindingmachine such as disclosed in the aforesaid patent to be more quickly setup for grinding different types of product camshafts. Another object ofthe invention is to provide a dog bar having a plurality of series ofactuating dogs and arranged so that any one of the series can be broughtopposite the member to be actuated. Another object of the invention isto provide a series of pointed out hereinafter.

The invention accordingly consists in the features of construction,combinations of elements, and arrangements of parts as will beexemplified in the structure to be hereinafter described, and the scopeof the application of which will be indicated in the following claims.

In the accompanying drawing illustrating one of many possibleembodiments of the mechanical features of this invention,

' Figure 1 is a perspective View of a camshaft grinder having theindexing mechanism of the present invention applied thereto;

Figure 2 is a view, partly in axial sectional view and partly inelevation, of the dog bar which is particularly a subject of the presentinvention, the center part of the dog bar being broken away;

Figure 3 is a sectional view taken on the line 3-3 of Figure 2;

Figure 4 is a sectional view taken on the line 4-4 of Figure 2;

Figure 5 is an isometric view of the dog bar.

In the grinding of cylindrical shafting it is suilicient to rotate theshaft on centers and bring into contact with it a rotating and(relatively) transversing grinding wheel. In order to grind camshafts,some means had to be provided to move the grinding wheel or work piece,one relative to the other, to generate the desired cam contour. In aline of machines exemplified by the patents hereinabove referred to, thegrinding wheel was mounted on a cross slide while the work piece wascarried by the table or carriage capable of a longitudinal move- (Cl. 51101) I ment. The work piece instead of being in a fixed position on thetable or carriage was mounted in centers provided in a rock bar. Thetable was moved from one position to another to bring successiveindividual cams opposite the grinding Wheel. A series of master camswere provided to rock the rock bar and a master cam roller was movableto a position opposite a particular master cam corresponding to theproduct cam to be generated. m

The design of the product camshaft being determined by automotiveengineering, it happened that the distance axially between successiveindividual cams was not uniform. In the patent to Silven No. 1,791,479referred to, the 15 motion of the carriage was used automatically tobring the master cam roller opposite the desired master cam, the mastercams being uniformly spaced. The apparatus of the present invention isshown embodied in a machine of this type..

Referring now to Figure l, the machine base is indicated at H] and onthe upper surface thereof are formed V ways H and a fiat Way l2 for thesupport of a carriage [3 having complementary V ways l4 and a flat way I5. This carriage I3 is, therefore, movable along the base 10 andautomatic hydraulic mechanism to move it is. disclosed in the aforesaidpatent to Belden and .Silven No. 2,022,178 while automatic me- 30chanical mechanism to move it is disclosed in patent to Belden andTrefethen .No. 1,945,588, and so far as the present invention isconcerned the carriage !3 might be manually moved to the variouspositions desired. 35.

Mounted on and afiixed to the carriage I3 is a table it, normallyextending parallel to it butcapable of slight angular adjustment, ifdesired. Mounted upon the table H5 in a bearing I8 and another bearingnot shown is a rock bar 20. 40 Fastened to the rock bar 20 is anadjustable tail center 21. The work piece or product camshaft W extendsbetween the adjustable. tail center 2| and the head center formed on theend of a master cam spindle 23 supporting a 45 plurality of master earns24. Fastened to the table It is a casting comprising a pair of bracketportions 25 and a connecting web 26, which casting supports a slideway27 for a rack 28.

Extending between the bracket portions 25 is a 5 of the brackets 25.Connected to the pinion gear 33 is a small spur gear 35 which mesheswith a somewhat larger spur gear 36 mounted on a stud 31 projecting froma lower portion 38 of the casting including the brackets 25. Meshingwith the gear 31 is another spur gear 46 mounted on a stud 4i projectingfrom a boss 42 also constituting part of the casting including brackets25 and the portion 38. On the end of the stud M is a star wheel 43. Thestar wheel 43 is a rotatable member and it is in effect a detent foractuating the rack 28 in a step by step movement responsive to contactwith the dogs to be hereinafter described.

The master cam spindle 23 is journalled in the rock bar 20 and as themaster cam spindle 23 revolves, the particular master cam 24 in contactwith the roller 3! causes the rock bar 20 to oscillate on the table l6.Thus a product cam will be formed of a shape controlled by a master cam24.

Any suitable means is provided to drive the product shaft W. Forexample, a motor, not shown, drives a worm 45 in a casing 46 on top of abracket 47 mounted on the table l6, and

' the worm meshes with a worm wheel 48 in a casing t9 connected to thebracket 61, the spur gear 18 being connected by a shaft 50 with a spurgear meshing with a spur gear 52 connected to a sprocket gear 53 whichis connected by a chain 54 to a sprocket gear 55 on the end of a shaft55, some of these parts being mounted in the casing 51 as indicated. Theshaft 56 is connected by a flexible coupling 53 to the master cam shaft23. Any suitable means involving a hydraulic cylinder 65 may be used torock the master cam shaft 23 away from the master cam roller 3| topermit indexing and this same motion will also move the product shaft Waway from the grinding wheel 66.

The foregoing is more fully described in the patents hereinbeforereferred to and, therefore, will not be further detailed herein.Referring now to all the figures, I provide a dog barwhich may consistof an end piece H and an end piece I2 mounted in journals '!3 and M inbrackets 15 and 16 fastened to the machine base l9. Each end piece H and12 has a portion which is square in cross section. The end piece H isrotatable to four different positions by means of a hand wheel 18 andmay be held in any of these positions by means of a spring pressedplunger 19 operated by a handle 88 which enters any one of four holes 8!in the bracket 15.

I further provide four removable dog bar sections 82 each comprising twobars rectangular in cross section and, as shown in Figure .5, spacedapart by blocks 83, the pair of bars being suitably fastened to theblocks and there being blocks 83 at each end of the bars. Each assemblyof the dog bar section 82 including the blocks 83 is fastened by meansof screws 85 to portions of the end pieces H and I2, respectively, whichare square in' cross section, and I may provide triangular prism blocks86 fastened to the end pieces fl and 12 securely to lock the dog barportions 82 in place.

I provide dogs 90 having enlarged bases SI and shanks 92 extendingthrough the slots 93 formed between the bars comprising the dog barsections 82 and secured in place by screws 94 and washers 95 locatedinside the dog bar. These dogs 90 operate on the star wheel to move themaster cam roller 3| whenever the table I6 is moved longitudinally, andthe dogs 90 can be spaced apart as desired on the dog bar. Furthermore,there may be four different arrangements of dogs 90 on the dog bar, oneat each side thereof. The dog bar sections 82 can readily be removed byremoving a pair of triangular prisms 86, one at each end of the dog bar,and a pair of screws 85 from the blocks 83. The machine may be madeready to grind different types of camshafts W simply by indexing the dogbar so far as the automatic positioning of the master cam roller 3! isconcerned.

Referring now to Figure 1, it is impossible for the dog bar to beindexed excepting when a cylindrical portion 96 of the end piece H isunder the star wheel 43. This is because in the turning of the dog bar,the prismatic shape thereof interferes with the stud 4| upon which thestar Wheel 43 is mounted. It should be understood that by making thedogs 90 longer, the dog bar would be turnable whatever the relativeposition of the star wheel, assuming no other parts interfere, but Iprefer to have this interlock so that the operator is required to movethe table to the extreme left-hand position (as he stands in front ofthe machine), that is to the right in Figure 1, before he can index thedog bar. Otherwise if the dog bar were turned at a point where therewere more dogs on one side of the star wheel in the case of one bar thanin the case of the other, the machine would be thrown out of timing.

It will thus be seen that there has been provided by this invention anapparatus in which the various objects hereinabove set forth togetherwith many thoroughly practical advantages are successfully achieved. Asmany possible embodiments may be made of the above invention and as manychanges might be made in the embodiment above set forth, it is to beunderstood that all matter hereinbefore set forth or shown in theaccompanying drawing is to be interpreted as illustrative and not in alimiting sense.

I claim:

1. In a camshaft grinding machine, the combination with a grindingtable, a rock bar mounted thereon, a master camshaft mounted on the rockbar, a master cam roller for contact severally with the master cams, andmechanism including a star wheel to move the master cam roller todifferent cams responsive to movement of the grinding table, of aplurality of dog bar sections parallel to each other and united andjournalled in the machine whereby any dog bar section may be broughtopposite the star wheel to actuate it.

2. In a camshaft grinding machine, the combination with a grindingtable, a rock bar mounted thereon, a master camshaft mounted on the rockbar, a master cam roller for contact severally with the master cams, andmechanism including a star wheel to move the master cam roller todifferent cams responsive to movement of the grinding table, of aplurality of rows of dogs and means for bringing any one row under thestar wheel to actuate it.

3. In apparatus of the class described, the combination with a pluralityof master cams, an abutment, mechanism for moving one of the foregoingrelative to the other to place the abutment selectively oppositedifferent master cams, said mechanism including a rotatable memberadapted to be actuated by dogs, of a plurality of sets of dogs andmounting means for the dogs permitting any one set to be broughtopposite the rotatable member.

4. In apparatus of the class described, the combination with a pluralityof master cams, an abutment, and mechanism for moving one of theforegoing relative to the other to place the abutment selectivelyopposite different master cams,

said mechanism including a detent adapted to be actuated by dogs, of aplurality of sets of. dogs and mounting means for the dogs permittingany one set to be brought opposite the detent.

v CLARENCE J. GREEN.

